I have noticed that sometimes when my car is just idleing that if I am outside of the car the engine knocks like a diesel truck...kinda. Does anyone else's do this?

 

Maybe you got a Cobalt TDI,lol.
Mine sounds normal.

 

Might be a worn chain tensioner

 

bad gas maybe

 

WARRANTY FTW!!!
Take that bad boy into the dealer

 

Piston Slap ,That goes away when it warms up or oil pressure comes up.
Get it checked out its to new for that.

 

injectors also make a loud clicking noise also

 

I have had this noise a few times, always happened after I been driving the car and started it back up a sort time after.

Took it into the dealer and because it was speractic, they didnt do anything about it and toldme unless it makes that noise all the time, we can't do anything.

 

i have that noise, but it doesnt sound like a major diesel engine. more like one of these volkswagon diesels except not even as bad as them. idk what the deal is either but i dont think its serious

 

yah my car kind of ticks also i may have them look at it next time I go in for a free oil change but I have always been ok with it. The ecotec is a pretty noisy engine.